Icy roads left much of the Paris region paralysed on Thursday after the heaviest snowfall in almost 25 years, with drivers advised not to use their cars unless absolutely necessary.

Interior Minister Brice Hortefeux asked drivers to leave their vehicles at home the day after 11 centimetres (more than four inches) of snow fell on Paris, the most since 1987.

Thousands of passengers spent the night at Roissy Charles de Gaulle airport after their flights were cancelled, and thousands more stranded motorists were put up in municipal halls and school sports halls around the Paris region.

In Velizy, southwest of Paris, between 7,000 and 8,000 people spent the night in company offices, at a shopping centre and in a sports hall.

"People were fatalistic, surprised and sometimes shocked," a town hall spokesman told AFP.

Authorities at the Eiffel Tower said they would reopen the landmark's first floor in the morning, and the rest of the monument progressively during the day after the weather forced its closure on Wednesday.

Salt cannot be used to fight snow or ice at the 324-metre (1,063-feet) tower because it would damage the iron structure that at this time of year gets around 12,000 visitors a day.

Amid rising public anger at the authorities perceived inability to deal with the situation, Hortefeux postponed a trip to Morocco.

The weather hit public transport in the suburbs hard, with around 50 of services affected, operator RATP said, including buses to Paris airports.

The traffic situation was expected to return to normal on Thursday afternoon, authorities said.